Check that all the services started up correctly and look in the logs in /var/log/nova for errors. If there are none, then Nova is up and running!
Note the network service should only be started on a single node, when setting up multiple compute nodes.

As of openstack-nova-2011.3-9.el6 and openstack-nova-2011.3-8.fc16, openstack-nova is now set up to use MySQL by default. If you're updating an older installation or prefer to set up MySQL manually instead of using the openstack-nova-db-setup script, this section shows how to do it.